refractive lens

Had she remembered to put in the refractive lenses?

Normally photographic cameras use refractive lenses (with the occasional reflective mirror) as their image forming optical system.

The issue of restoring accommodation following cataract surgery or through refractive lens exchange is becoming an increasingly important topic in ophthalmology.

But X-rays are refracted only slightly, so the only practicable refractive lenses have been compound ones, made up of many lenses in a line.

For some, accommodating IOLs may be a better alternative to refractive lens exchange (RLE) and monovision.

Refraction is the basis for the compound refractive lens, many small X-ray lenses in series that compensate by their number for the X-rays' minute index of refraction.

This makes them much shorter, lighter, and cheaper than an all refractive lens, but at the cost of some optical compromises due to aberrations caused by the central obstruction from the secondary mirror.

If the X-ray source isn't collimated, as with a synchrotron radiation, elementary collimating mirrors or diffractive lenses are used in the place of the refractive lenses used in optics.

A Compound refractive lens (CRL) is a series of individual lenses arranged in a linear array in order to achieve focusing of X-rays in the energy range of 5-40 keV.

It was the kind of thing that was only noticed by people who spent their nights on rooftops, counting the hours and days, shrugging off the dew, and staring at bits of the night through long refractive lenses.

Moreover, chromatic aberration, a major problem with long refractive lenses, and off-axis aberration, a major problem with reflective telescopes, is almost completely eliminated by the catadioptric system, making the image they produce suitable to fill the large focal plane of a camera.

When compared with clear lens extraction, or refractive lens exchange the PIOL has the advantage of preserving natural accommodation and may have a lower risk of postoperative retinal detachment because of the preservation of the crystalline lens and minimal vitreous destabilization.